To improve silicon heterojunction solar cells even further, minimizing transport losses within the charge carrier selective junctions and layers is mandatory. With this in mind, we present a systematic quantification of the transport losses of the electron (contact resistivity, ρc ≈ 30 mΩ·cm²) and hole (ρc ≈ 240 mΩ·cm²) contact of our silicon heterojunctions, which enable fill factors above 80% on cell level. We identify the cause of the higher transport losses of the hole contact to be the intrinsic a-Si:H and ITO layer and that these layers are also responsible for a limited thermal stability. Furthermore, temperature-dependent I–V measurements reveal the nonohmic nature of the transport losses in case that intrinsic a-Si:H and transparent conductive oxide are part of the heterojunction.

中文翻译：

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TCO/a-Si:H/c-Si 异质结处的传输损耗：不同层和退火的影响

为了进一步改进硅异质结太阳能电池，必须最大限度地减少电荷载流子选择性结和层内的传输损失。考虑到这一点，我们对我们的硅异质结的电子（接触电阻率，ρc ≈ 30 mΩ·cm²）和空穴（ρc ≈ 240 mΩ·cm²）接触的传输损耗进行了系统量化，这使得填充因子能够超过 80细胞水平上的百分比。我们确定空穴接触较高传输损耗的原因是本征 a-Si:H 和 ITO 层，并且这些层也是导致有限热稳定性的原因。此外，在本征 a-Si:H 和透明导电氧化物是异质结的一部分的情况下，与温度相关的 I-V 测量揭示了传输损耗的非欧姆性质。